Actually if the 4 of them are in for nomination for PE, that will be the best.
It will be a shame if any one withdraws out now. But if it is TT whom withdraws, then that is another different scenario.
If TT is in, the other 3 candidacy-eligibles, should go on.
The worst show is to have 2 candidates because that will undermine the other with lesser or no unions' support, no media support, etc, to contest in an obviously unfair and bias manner with TT.
However if it is a 3 candidates election, then at least it will be a 33.33%, or a spread between the media attention to focus on the two.
The best is to have more candidates, however not too much either, otherwise more than 4 will kill the soup.
4 is just the best for the nomination to run beautiful and all of them to run in good fight.
After all that hoo-ha to gain qualification, anyone who is giving up at this stage before nomination day is just a joke on themselves and undermining the seriousness of the PE, and definitely be a few slashes across their reputation.
First round of talks completed. Watch this space.